A relation between time-resolved discharge parameters and ageing

A study is described relating discharge data from large bandwidth electrical and optical measurements with ageing phenomena in polyethylene (PE) voids. Discharge-pulse shape, ignition voltage and spatial distribution of the discharge were monitored in disc-shaped voids during ageing. A link was made between the deposit of discharge by-products and the occurrence of minute discharge pulses by optical means. The electrical and optical parameters changed drastically during ageing and may be used as indicators for the stage of ageing that has been reached